Diesel High Pressure Oil Pumps (HPOPs)

Diesel engines use high-pressure oil pumps (HPOPs) to deliver pressurized oil to the fuel injectors. The injectors need pressurized oil to compact the fuel before it enters the combustion chamber, so it burns as a fine mist. The HPOP configuration depends on the engine make/model. Some are mounted to the front cover of the lifter valley; others are mounted directly to the engine at the back of the crankcase. 

The pump is controlled by the Powertrain control module, which uses the injection pressure regulator (IPR) to control the oil output. The IPR is pulse-width actuated, which determines the amount of oil being released through the pistons and the resulting psi level based on how much is needed to power the engine at the current RPM, temperature and load.

The condition of the pump affects fuel efficiency. Reduced oil pressure prevents the injectors from pressurizing the fuel, which makes it harder for the engine to burn, leading to lower mpg ratings. Your truck’s HPOP is a reflection of the oil you put into the engine. Not changing oil every 5,000 to 7,000 miles, excessive towing, using poor-quality oil and not replacing your oil filters can clog the pump with soot and debris, limiting the flow of oil. Less oil also reduces lubrication throughout the engine, increasing wear and tear.

HPOPs generally last 150,000 to 300,000 miles, depending on the make and model. Clogs and debris will prevent the seals from closing properly, which could leak oil into the exhaust and release blue smoke out of the tailpipe.

Shop for a replacement high-pressure oil pump and all other quality diesel products by make/model, production year or manufacturer to increase the flow of oil in your engine.